docs: def map_age(age):
          """ Map age to correct age-group. """
  
          if age in [None, '']:
              return issuers.AgeGroup.UNKNOWN
          elif age == 'teens':
              return issuers.AgeGroup.YOUTH
          elif age in ['sixties', 'seventies', 'eighties', 'nineties']:
              return issuers.AgeGroup.SENIOR
          else:
              return issuers.AgeGroup.ADULT